Art galleries, museums, jewelry stores and gift shops often display valuable works of art or articles for sale such as sculptures, pieces of jewelry, and the like, in the open where they can be seen best and admired by viewers and prospective purchasers. When precious pieces of art are placed in or behind obtrusive glass cases, the viewing of the pieces so located is considerably impaired. A problem exists, however, with the placement of valuable pieces of art, particularly small pieces, on display in the open in the increased incidence of thefts of such openly displayed sculptures, jewelry, and the like, from galleries, museums, and stores using such a display technique.
Systems have been developed for use in art galleries and museums which generally provide an intrusion protection against break-in from the outside during the times the museums or galleries are closed. Such alarm systems, obviously, are worthless during normal business hours when they are deactivated in order to permit the normal operation of the business.
Many museums and some art galleries have displays wired into a permanently wired alarm system which includes various sensors, switches, and the like, activated whenever a piece protected by the system is moved. Permanently wired systems, however, are expensive and relatively inflexible. If a rearrangement of the gallery or frequent changing of displays and types of displays is desired, permanently wired systems, at any cost, are not a practical solution to providing alarm protection against thefts of the works of art on display.
Self-contained alarm units, either built into a briefcase, box, or the like, or included as part of a separate base, have been developed in the past. One such alarm is disclosed in the patent to Stelter, U.S. Pat. No. 2,797,405. This patent discloses a jewelry box or similar article with a pin extending through a hole in the bottom of the box. The pin is of sufficient length to rest against the inside of the lid of the box when the lid is closed and extends through the bottom of the box. A special base, including the alarm components, is provided onto which the box is placed. The pin extends through a hole in the upper surface of the base to normally press against a spring biased switch contact, holding the switch in an open circuit position. An alarm is connected in series with the switch and a battery. If the lid is opened, the pin is pushed upwardly by means of the spring bias of the switch, permitting the switch to close and energize the alarm. Similarly, if the box is picked up off the base, the pin is removed and the spring closes the switch with the same result. The alarm requires a specially constructed box for containing the valuables to be protected, and in addition, requires use of that box with the specially constructed base, including the alarm components.
Other types of movement actuated alarm switches are disclosed in a variety of patents, a typical one of which is the patent to Bennett, U.S. Pat. No. 3,685,037, issued Aug. 15, 1972. This patent discloses a spring biased switch extending through a base support connected to the bottom of a business machine. If the machine is lifted, the spring biased switch closes and activates an electronic circuit to engage a buzzer alarm. The alarm can be deactivated subsequently only by opening a key operated switch in the series circuit of the alarm circuit. Various types of audible and visual alarms utilizing built-in switches in specially constructed boxes, or utilizing pressure depressed spring biased switches in the bottom of display racks, and the like, have been used in the past.
A disadvantage with the prior art alarm devices is that they either are not self-contained or if they are, the alarms themselves are constructed as an integral part of a specially constructed box or the like for containing valuables. In the case of alarms for display racks, the rack itself is specially constructed; and if the rack and the object being protected are simultaneously moved, no alarm is sounded.
It is desirable to provide a relatively small, inexpensive, self-contained, portable alarm which may be used for protecting openly displayed valuable articles and which may be activated when either the article is removed or when the article and the alarm unit are removed together. It is desirable particularly to provide for a portable self-contained alarm which may be used without restriction wherever an article of art or the like is desired to be displayed.